Technical Field
The present invention relates to a vertical-axis wind power generator. More particularly, the present invention relates to a vertical-axis wind power generator having adjustable-angle rotating blades, which can maximize power generation efficiency through angle adjustment of the rotating blades for upper and lower support arms so that the maximum forward-rotation wind power and the minimum reverse-rotation wind power are applied to the rotating blades, and forward rotation can be performed even by the reverse-rotation wind power in a partial angle range.
Background Art
In general, a wind power generator is briefly classified into a horizontal-axis wind power generator and a vertical-axis wind power generator in accordance with a method for installing a main shaft.
The horizontal-axis wind power generator is a propeller-shaped wind power generator in which rotating blades are installed on the horizontal axis, and requires a wind speed of 6 to 15 m/s for the rated power. However, in most places in this country, except for specific regions, in which the wind speed is high, such as Jeju Island and Daeguanryoung, the wind speed is low to cause the power generation efficiency to be lowered, and thus it is not possible to install the horizontal-axis wind power generator in such places.
Most regions of the interior or the seaside of this country belong to low wind speed regions in which the wind speed is lowered to about 2 to 5 m/s, and in such low wind speed regions, the vertical-axis wind power generator in which rotating blades are installed on the vertical axis has been used so as to achieve constant wind power generation regardless of the wind direction.
However, since the rotating blades used in the vertical-axis wind power generator are fixed to support arms of a rotating body that is rotatably installed around a main shaft, the rotating blades can revolve around the main shaft in accordance with the rotation of the rotating body, but are unable to rotate on the support arms of the rotating body. Accordingly, the rotating blades may receive the forward-rotation wind power being applied thereto through the revolution around the main shaft, may not receive the wind power at all to transfer no rotating power to the main shaft, or may receive the reverse-rotation wind power to deteriorate the wind power generation efficiency.
Further, in the case where rotating blades of a streamlined wing shape are used, only concave portions of the streamlined wings that are against the wind direction can receive the wind power to cause only a half of the wind power to be used, and great wind resistance occurs on convex portions of the streamlined wings that are against the wind direction. In the case where wind gate type blades are used, wind gates on the reverse-rotation side are opened to reduce the wind resistance, but the wind power that is necessary for rotation acts on only portions except for the opened wind gates to deteriorate the wind power generation efficiency.
As an example of a wind power generator to solve the above-described problems, Korean Unexamined Patent Publication No. 10-2011-0015237 (published on Feb. 15, 2011) discloses an apparatus for adjusting the direction of rotating blades for a vertical-axis wind power generator to adjust the direction of the rotating blades using a rotating force of a weathercock, which includes a weathercock, a sensor sensing a rotating angle by a wind direction of the weathercock, a power generation means for transferring the rotating force according to a sensing signal of the sensor, a controller controlling driving of the power generation means through reception of the rotating angle sensing signal of the sensor, a first bevel gear rotating according to generated power of the power generation means, a first planet gear of a predetermined rate that is tooth-engaged with the first bevel gear, a second planet gear connected to the first planet gear through a shaft having a predetermined length, a second bevel gear of a predetermined rate, that is tooth-engaged with the second planet gear, and rotating blades of a predetermined length that is fixed to a shaft of the second bevel gear, wherein the rotating force according to a change of the wind direction of the weathercock is transferred to the rotating blades to adjust the direction of the rotating blades.
However, according to the above-described vertical-axis wind power generator in the related art, the rotating blades are rotated at a constant speed during the revolution around the main shaft, and thus there are limits in applying the maximum forward-rotation wind power and the minimum reverse-rotation wind power to the rotating blades.
Further, according to the above-described vertical-axis wind power generator in the related art, if the wind speed is low, the power generation may not be properly performed, while if the wind speed is too high, the wind power generator may be damaged or troubled due to excessive rotations.